The present invention relates generally to a method of and apparatus for decontaminating radioactive garments, and more specifically, the removal of radioactive dust, dirt, grease, oil, water and loose surface contamination from protective clothing and accessory protective articles by dry cleaning such articles.
The conventional method of cleaning radioactive particulate material from industrial worker's protective clothing is a conventional wet laundry wash. This wash entails a standard 30 to 45 minute water washing using commercial detergents followed by a separate drying cycle (usually 60 minutes) in a conventional hot air or other type textile clothes dryer. This system normally is so inefficient that from twenty (20%) percent to thirty-five (35%) of the protective clothing must be rewashed because insufficient radioactivity has been removed to permit reuse of the protective article. Moreover, approximately three (3) gallons of contaminated wash water is generated per 16 pounds of clothing washed. This water must be diluted to a safe concentration before it is released or evaporated to a concentrate, and then drummed and buried at an approved radiation waste burial facility. This makes the process very costly and time consuming. Further, the conventional wet laundry involves the wash cycle followed by a separate drying cycle in a hot air dryer. In the event that insufficient radioactive particulate is removed, the heat fixes the contaminated dirt to the cloth fibers which makes successive cleanings much less efficient and results in an early discard of the protective garments.
In an effort to eliminate some of these difficulties, dry cleaning systems have been suggested which use hydrocarbon solvents. Conventionally, these solvents have a relatively low boiling point, such as that of perchloroethylene, and the vapors from such materials have been hazardous to the personnel operating such cleaning systems. Moreover, the conventional dry cleaning systems, such as discosed in U.S. Pat. No. 3,728,074, have not provided any better cleaning results than the conventional wet wash system.
Accordingly, it is a primary object of the present invention to provide a method of and apparatus for decontaminating radioactive garments by using a dry cleaning solvent which continuously flushes the radioactive particulate material separated from the garment into a sump during the wash cycle.
Further, it is an object of the present invention to provide a method of and apparatus for decontaminating radioactive garments in a single apparatus which dries the garments after completion of the wash cycle.
Further, it is an object of the present invention to provide a method of and apparatus for decontaminating radioactive garments which continuously flushes the garments with circulating solvent during the wash cycle and adds a clean solvent to the drum at the beginning of the wash cycle to dilute any radioactive contamination within the re-cycled solvent.
Further, it is an object of the present invention to provide a method of and apparatus for decontaminating radioactive garments which removes any radioactive particulate material settling out of the re-cycling solvent.
Further, it is an object of the present invention to provide a method of and apparatus for monitoring the amount of radioactivity in the re-cycling solvent to ensure that adequate filtering removes the radioactive particulate material from such solvent.
Further, it is an object of the present invention to provide a method of and apparatus for decontaminating radioactive garments which uses 0.5 micron filters for continuously filtering re-cycled solvent during both wash and dry cycles to remove substantially all of the radioactive particulate material suspended in such solvent.
Further, it is an object of the present invention to provide a method of and apparatus for filtering the solvent upon removal from a drum which agitates the garments during the wash cycle for removing lint from such solvent before it is continuously filtered.
In accordance with the invention, a method of decontaminating radioactive garments comprises the steps of depositing the garments in a cleaning drum or cage and agitating the drum during a wash cycle. Further, a dry cleaning solvent is continuously added to the drum during the wash cycle and continuously removed therefrom to flush radioactive particulate material separated from the garments into a sump. The solvent is then pumped from the sump to the drum for use to continuously flush the radioactive particulate matter therefrom. During such pumping, the solvent is filtered to remove substantially all of the radioactive particulate material suspended in the solvent.
Further, in accordance with the invention, an apparatus for decontaminating radioactive garments comprises a drum for supporting the radioactively contaminated garments during wash and dry cycles. Means are used for continuously flushing any radioactive material separated from the garments out of the drum during the wash cycle with a dry cleaning solvent. A sump receives the solvent and the material flushed out of the drum and the solvent is filtered to remove the radioactive particulate materials suspended therein prior to the solvent being used to again flush the radioactive material out of the drum.
Further, in accordance with the invention, apparatus is provided for decontaminating radioactive garments which comprises a sump for storing a dry cleaning solvent and a drum for agitating the radioactively contaminated garments during a wash cycle which separates radioactive particulate material from the garments. The dry cleaning solvent is continuously pumped from the sump to the drum and the solvent and separated particulate material is continuously removed from the drum into the sump. The dry cleaning solvent which is continuously pumped to the drum is filtered to remove substantially all of the particulate material from the solvent which permits the solid entrapped radioactive waste and filter to be the main item of disposal at an approved radiation waste disposal facility.